Former Mayer Brown chairman Tyrone Fahner said he made a mistake by using firm letterhead to write a letter in support of former Speaker of the House Dennis Hastert who faces sentencing Wednesday in connection with a hush-money scandal.

U.S. District Judge Thomas Durkin on Friday made Fahner’s letter public along with 40 others supporting Hastert, who pleaded guilty to a financial crime prosecutors say was related to paying off one alleged victim of Hastert’s sexual abuse in the 1960s and 1970s.